Table 2

Densitometric progression ('raw' data)

Mean ± SD
Baseline
Follow-up
Change from baseline
t
p value
Annual change

WL Perc15 (HU)
-939.09 ± 33.44
-946.16 ± 29.26
-7.06 ± 8.97
-6.64
< 0.0001
-3.53
WL VI-950 (%)
15.08 ± 10.63
17.75 ± 11.35
2.67 ± 3.34
6.74
< 0.0001
1.34
WL VI-910 (%)
36.29 ± 18.28
40.48 ± 18.06
4.18 ± 5.14
6.86
< 0.0001
2.09

WL, whole lung; Perc15,15th percentile point (measured in Hounsfield Units); SD, standard deviation; VI-950, voxel index at a threshold of -950HU (measured in %); VI-910, voxel index at a threshold of -910HU (measured in %); annual change, change in outcome measure without adjustment for lung volume.

Parr et al. Respiratory Research 2008 9:21   doi:10.1186/1465-9921-9-21